Document Detail

The effect of Q Factor on gross mechanical efficiency and muscular activation in cycling.
MedLine Citation:
PMID:  22612455     Owner:  NLM     Status:  Publisher    
Unexplored in scientific literature, Q Factor describes the horizontal width between bicycle pedals and determines where the foot is laterally positioned throughout the pedal stroke. The aim of the study was to determine whether changing Q Factor has a beneficial effect upon cycling efficiency and muscular activation. A total of 24 trained cyclists (11 men, 13 women; VO(2max) 57.5 ml·kg/min ± 6.1) pedaled at 60% of peak power output for 5 min at 90 rpm using Q Factors of 90, 120, 150, and 180 mm. Power output and gas were collected and muscular activity of the gastrocnemius medialis (GM), tibialis anterior (TA), vastus medialis (VM), and vastus lateralis (VL) measured using surface electromyography. There was a significant increase (P < 0.006) in gross mechanical efficiency (GME) for 90 and 120 mm (both 19.38%) compared with 150 and 180 mm (19.09% and 19.05%), representing an increase in external mechanical work performed of approximately 4-5 W (1.5-2.0%) at submaximal power outputs. There was no significant difference in the level of activity or timing of activation of the GM, TA, VM, and VL between Q Factors. Other muscles used in cycling, and possibly an improved application of force during the pedal stroke may play a role in the observed increase in GME with narrower Q Factors.
B X Disley; F-X Li
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Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-5-21
Journal Detail:
Title:  Scandinavian journal of medicine & science in sports     Volume:  -     ISSN:  1600-0838     ISO Abbreviation:  -     Publication Date:  2012 May 
Date Detail:
Created Date:  2012-5-22     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9111504     Medline TA:  Scand J Med Sci Sports     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
© 2012 John Wiley & Sons A/S.
School of Sport and Exercise Sciences, University of Birmingham, Birmingham, UK.
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